Plugging and diverting acid fracturing is an indispensable and promising technology that aims to enhance productivity for complex carbonate reservoirs. The key to success for this technology is the formation of effective plugged zones within preexisting fractures. However, because fracture pattern before and after acid-etching is quite different, the plugging behavior of fibers and particulates within acid-etched fractures is correspondingly distinct with respect to within smooth and hydraulic fractures. Till now, a number of researches have been studied on plugging experiments with various apparatuses. However, the plugging laws within acid-etched fracture are still unclear, and the experimental results are insufficient in revealing specific plugging laws, particularly with respect to fracture morphology. In this paper, we propose new parameters to analyze fracture morphology and introduce an integrated experimental method as well to study plugging behavior within fractures with different morphologies. Firstly, we obtain acid-etched fracture profiles with a 3D scanner and reproduce the rough physical-model fracture using 3D printing technology. Then, we perform a series of experiments to grasp plugging laws. Finally, in terms of fracture features analysis and experimental results, we further analyze the correlation between plugging behavior and surface morphology. The calculation results of digital parameters show that after acid-etching the roughness of the whole fracture increases due to acid-rock interaction, and channels are formed along the flow direction. Meanwhile experimental results show that flat fractures are relatively difficult to be plugged with respect to rough fractures because it has corresponding lower abilities to capture fibers and particulates. Pure fibers can independently plug 2 mm-wide fractures, as fracture width increased, the addition of particulates will improve the plugging efficiency. Additionally, fracture surface morphology has a huge influence on plugging behavior and dominate the possibility of plugging formation. Plugged zones generally are formed in the roughest areas of the fracture.

封堵和转移酸压裂是必不可少且有希望的技术，旨在提高复杂碳酸盐岩油藏的生产率。这项技术成功的关键是在现有裂缝中形成有效的堵塞区域。但是，由于酸蚀之前和之后的断裂方式有很大不同，因此酸蚀断裂中纤维和颗粒的堵塞行为相对于光滑和水力断裂而言是截然不同的。迄今为止，已经对各种设备的堵塞实验进行了许多研究。但是，酸蚀裂缝内的堵塞规律尚不清楚，实验结果不足以揭示具体的堵塞规律，特别是在裂缝形态方面。在本文中，我们提出了用于分析裂缝形态的新参数，并引入了一种综合实验方法来研究具有不同形态的裂缝内的堵塞行为。首先，我们使用3D扫描仪获得酸蚀后的裂缝轮廓，并使用3D打印技术重现粗糙的物理模型裂缝。然后，我们进行了一系列实验以了解堵塞规律。最后，根据断裂特征分析和实验结果，我们进一步分析了堵漏行为与表面形态之间的关系。数字参数的计算结果表明，酸蚀后，由于酸岩相互作用，整个裂缝的粗糙度增大，沿流动方向形成通道。同时，实验结果表明，相对于粗糙裂缝而言，扁平裂缝相对难以堵塞，因为它具有较低的捕获纤维和微粒的能力。纯纤维可以独立堵塞2毫米宽的裂缝，随着裂缝宽度的增加，添加颗粒将提高堵塞效率。另外，裂缝表面形态对堵塞行为有很大的影响，并决定了堵塞形成的可能性。通常在裂缝的最粗糙区域形成堵塞区域。裂缝表面形态对堵塞行为有很大的影响，并决定了堵塞形成的可能性。通常在裂缝的最粗糙区域形成堵塞区域。裂缝表面形态对堵塞行为有很大的影响，并决定了堵塞形成的可能性。通常在裂缝的最粗糙区域形成堵塞区域。